1. Field of the Invention
The present invention is concerned with certain novel pyrazolo[1,5-a]pyridine and 4,5,6,7-tetrahydropyrazolo-[1,5-a]pyridine derivatives, which have inhibitory activities on platelet aggregation and are useful for treating cerebral and peripheral vascular insufficiencies and accompanying complications containing them.
Recently, it is generally accepted that platelets and/or products of arachidonic acid metabolism have an important role in the etiology of thrombotic diseases and arteriosclerosis. Therefore, developments of much more valuable antiaggregants have been largely desired.
As a result of the intense investigation, the present investigators have now unexpectedly found that new derivatives of pyrazolo[1,5-a]pyridine and 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine possess a potent inhibitory activity on platelet aggregation. This is unobvious from the known arts of the similar series. ##STR1## [Wherein, R is lower alkyl. A is tetrahydro-3-pyridyl which may be substituted at the N-position by lower alkyl, or R.sup.1 --NHCO-- (wherein R.sup.1 is a phenyl group which may be substituted), or 3-pyridyl group].
Thus the present compounds are useful as agents for preventing or treating, for example, cerebrovascular disease, thrombosis, migrainia, local anemic infarction, myocardial ischemia and infarction, vascular complications accompanied with cancer or diabetes, and so on.
The compounds or their salts are used in human and veterinary medicine in intact or in pharmaceutical compositions, which additionally comprise an inert physiologically acceptable carrier. For oral or parenteral administration, suitable forms of pharmaceutical composition are, for example, compressed tablets, capsules, liquors, injections, suppositories, powders, syrups and so on.